2004 DODGE RAM 2500 DIESEL cooling

12. ABS Warning Light
This light monitors the Anti-Lock Brake System
which is described elsewhere in this manual. This
light will come on when the ignition key is turned to the
ON position and may stay on for five seconds. If the ABS
light remains on or comes on during driving, it indicates
that the anti-lock portion of the brake system is not
functioning and that service is required. See your autho-
rized dealer immediately. The ABS light could also
illuminate during loss of traction and remain illuminated
until the brake pedal is pressed.
13. Temperature Gauge
The temperature gauge indicates engine coolant
temperature. Any reading within the normal
range indicates that the cooling system is operat-
ing satisfactorily. The gauge needle will likely indicate a
higher temperature when driving in hot weather, up
mountain grades, in heavy traffic, or when towing a
trailer. If the needle rises to the ª245ÉFº mark, stop thevehicle, shift into N (Neutral), and increase the engine
idle speed for 2 to 3 minutes. If the temperature reading
does not return to normal, shut your engine OFF and
allow it to cool. Seek authorized service immediately. See
Cooling System information in the section on ªMaintain-
ing Your Vehicle.º
CAUTION!
Do not leave your vehicle unattended with the
engine running as you would not be able to react to
the temperature indicator if the engine overheats.
NOTE:Engine idle speed will automatically increase to
1000 rpm at elevated coolant temperatures to improve
engine cooling.
146 UNDERSTANDING YOUR INSTRUMENT PANEL

snowflake button shows that the air conditioning is on.
Press the button a second time to turn the air condition-
ing off.
Slight changes in engine speed or power may be noticed
when the air conditioning compressor is on. This is a
normal occurrence as the compressor will cycle on and
off to maintain comfort and increase fuel economy.
The mode control (at the right of the
control panel) can be set in any of the
following positions:
NOTE:To improve your selection choices, the system
allows you to operate at intermediate positions between
the major modes. These intermediate positions are iden-
tified by the small dots.Recirculation Modes (Panel or Bi-Level )
Select the recirculation modes when
the outside air contains smoke, odors,
high humidity, or if rapid cooling is
desired. This feature allows for recir-
culation of interior air only. Air flows
through the panel outlets in this mode.
NOTE:Selecting a ªRecirculation Modeº mode does not
necessarily consume more fuel than normal A/C mode.
Panel
Outside air flows through the outlets located in the
instrument panel.
Bi-Level
Outside air flows through the outlets located in the
instrument panel and at the floor.
188 UNDERSTANDING YOUR INSTRUMENT PANEL

speeds will reduce fogging. Interior fogging on the
windshield can be quickly removed by selecting the
defrost mode.
Regular cleaning of the inside of the windows with a
non-filming cleaning solution (vinegar and water works
very well) will help prevent contaminates (cigarette
smoke, perfumes, etc.) from sticking to the windows.
Contaminates increase the rate of window fogging.
Summer Operation
Air conditioned vehicles must be protected with a high
quality antifreeze coolant during summer to provide
proper corrosion protection and to raise the boiling point
of the coolant for protection against overheating. A 50 %
concentration is recommended. Refer to Recommended
Fluids and Genuine Parts for the proper coolant type.
When using the air conditioner in extremely heavy traffic
in hot weather especially when towing a trailer, addi-
tional engine cooling may be required. If this situation isencountered, operate the transmission in a lower gear to
increase engine RPM, coolant flow and fan speed. When
stopped in heavy traffic, it may be necessary to shift into
NEUTRAL and depress the accelerator slightly for fast
idle operation to increase coolant flow and fan speed.
NOTE:On models equipped with Diesel engines, the
idle speed will automatically increase to 1000 rpm at
elevated coolant temperatures to improve engine cooling.
Your air conditioning system is also equipped with an
automatic recirculation system. When the system senses
a heavy load or high heat conditions, it may use partial
Recirculation A/C mode to provide additional comfort.
Winter Operation
When operating the system during the winter months,
make sure the air intake, located directly in front of the
windshield, is free of ice, slush, snow, or other obstruc-
tions.
UNDERSTANDING YOUR INSTRUMENT PANEL 197
4

NOperating Precautions..................216
NCooling System Tips Ð Automatic
Transmission........................216
mTransmission Shifting....................218
NFour-Speed Overdrive Automatic
Transmission Ð If Equipped.............218
NManual Transmission ± 5±Speed
(NV- 4500) Ð If Equipped...............222
NManual Transmission Ð 6-Speed
(NV-5600) Ð If Equipped...............224
mFour-Wheel- Drive Operation Ð If Equipped . . . 226
NManually Shifted Transfer Case Operating
Information/Precautions................226
NShifting Procedure - Manually Shifted Transfer
Case..............................229NTransfer Case Reminder Light............230
NElectronically Shifted Transfer Case
Operating Information/Precautions........230
NShifting Procedure - Electronically Shifted
Transfer Case........................234
mLimited-Slip Differential Ð If Equipped.......237
mParking Brake.........................238
mBrake System..........................239
NBrake Noise.........................240
NFour-Wheel Anti-Lock Brake System........240
mPower Steering........................242
mTire Safety Information...................243
NTire Markings........................243
NTire Identification Number (TIN)..........246
200 STARTING AND OPERATING

NTrailer Towing Ð Hitches...............275
NConnecting Trailer Lighting And Electric
Trailer Brakes........................276
NTrailer Weight And Trailer Tongue Weight....278
NTrailer Towing Information
(Maximum Trailer Weight Ratings).........279
NTrailer Towing Mirrors Ð If Equipped......279
NCooling System Tips Ð Trailer Towing......280
NAutomatic Transmission Oil Temperature
Warning Light.......................281
NTowing With An Automatic Transmission....281
mSnowplow............................282
NBefore Plowing.......................283
NSnowplow Prep Package Model Availability . . 283NOver The Road Operation With Snowplow
Attached...........................284
NMethods For Removing Snow............284
NOperating Tips.......................284
NGeneral Maintenance...................285
mRecreational Towing Ð 4±Wheel Drive Vehicles
(Behind Motorhome, Etc.).................286
NRecreational Towing Procedure Ð Manual
Shift Transfer Case Ð If Equipped.........286
NReturning To Normal Operation Ð Manual
Shift Transfer Case....................287
NRecreational Towing Procedure Ð Electronic
Shift Transfer Case Ð If Equipped.........288
NReturning To Normal Operation Ð Electronic
Shift Transfer Case....................290
202 STARTING AND OPERATING

WARNING!
Remember to disconnect the cord before driving.
Damage to the 110±115 volt electrical cord could
cause electrocution.
NOTE:The block heater will require 110 Volts AC and
6.5 Amps to activate the heater element.
Block Heater Usage
A.Temperatures below 0ÉF (-18ÉC)
²Block Heater Required for 15W-40
²Block Heater Recommended for 5W-40
B.Temperatures below - 20ÉF (-29ÉC)
²Block Heater Required for 5W-40
Winter Front Usage
If a winter front or cold weather cover is to be used, a
percentage of the total grille opening area must be left
uncovered to provide sufficient air flow to the charge air
cooler and automatic transmission oil cooler. The per-
centage of opening must be increased with the increasing
ambient air temperature and/or engine load. If the
cooling fan can be heard cycling frequently, increase the
size of the opening in the winter front. A suitable cold
weather cover is available from your Mopartdealer.
Battery Blanket Usage
A battery loses 60% of its cranking power as the battery
temperature decreases to 0ÉF (-18É). For the same de-
crease in temperature, the engine requires twice as much
power to crank at the same RPM. The use of 120 VAC
powered battery blankets will greatly increase starting
capability at low temperatures. Suitable battery blankets
are available from your authorized Mopartdealer.
STARTING AND OPERATING 213
5

Engine Speed Control
CAUTION!
Prevent overspeeding the engine going down hill.
When descending steep grades, use a combination of
gears and service brakes to control vehicle/engine
speed. Overspeed can cause severe engine damage.
Operating Precautions
Avoid Overheating The Engine
The temperature of the coolant (a mixture of 50%
ethylene-glycol and 50% water) must not exceed the
normal range of the temperature gauge (240ÉF/116ÉC)
with a 16 psi (110 kPa) radiator cap.
Usually the coolant temperature indicated during opera-
tion will be to the left of center in the normal range of the
gauge.
Avoid Low Coolant Temperature Operation
Continual operation at low coolant temperature below
the normal range on the gauge (140ÉF/60ÉC) can be
harmful to the engine. Low coolant temperature can
cause incomplete combustion which allows carbon and
varnish to form on piston rings and injector nozzles.
Also, the unburned fuel can enter the crankcase, diluting
the lubricating oil and causing rapid wear to the engine.
Cooling System Tips Ð Automatic Transmission
To reduce potential for engine and transmission over-
heating in high ambient temperature conditions, take the
following actions:
²City Driving Ð
when stopped, put transmission in neutral and increase
engine idle speed.
NOTE:The engine speed will automatically increase to
1000 RPM at elevated coolant temperature to improve
engine cooling.
216 STARTING AND OPERATING

ª1º First
Use this position for driving up very steep hills and for
engine braking at low speeds 20 mph (32 km/h) or less
when going downhill. To prevent excessive engine speed,
do not exceed 25 mph (40 km/h) in this range.
NOTE:Use caution when operating a heavily loaded
vehicle in ª2º Second or ª1º First gear selections in high
ambients as torque converter slip can impose significant
additional heat load on the cooling system.
WARNING!
Never use Park position on an automatic transmis-
sion as a substitute for the parking brake. Always
apply parking brake fully when parked to guard
against vehicle movement and possible injury or
damage.
Overdrive Operation
The four-speed overdrive automatic transmission con-
tains an electronically controlled fourth speed (Over-
drive). The transmission will automatically shift from
Drive to Overdrive if the following conditions are
present:
²the transmission selector is in Drive;
220 STARTING AND OPERATING